1. Field of the Invention
The present invention relates to a gear shift device for a vehicle automatic transmission, and more particularly to an interlock and shift lock device for a gear shift lever.
2. Description of Related Art
A known gear shift device for a vehicle automatic transmission provides an interlock or anti-theft lock device which cooperates with a gear shift lever. The interlock device disables the gear shift lever, when the lever is in a parking position, and prevents it from shifting the transmission when the engine is switched off. The device also enables an ignition key to be pulled out from an ignition assembly when the gear shift lever has been placed in the parking position. Such gear shift devices are disclosed, for example, in Japanese Unexamined Patent Publication No. 60-135,352, published July 18, 1985, and Japanese Unexamined Utility Model Publication No. 59-176,253, published Nov. 26, 1984.
Another known gear shift device for a vehicle automatic transmission provides a shift lock device which cooperates with the gear shift lever for disabling the gear shift lever, when the lever is in a parking position, to prevent the gear shift lever from shifting whenever a brake pedal is released, and for enabling the gear shift lever, when the lever is in the parking position, to be moved to other positions upon depression of the brake pedal. Such a gear shift device is disclosed in, for example, Japanese Unexamined Utility Model Publication No. 62-202,433, published Dec. 24, 1987. It should be noted that a gear shift device cooperating systematically with both an interlock device and a shift lock device is desired to improve the safety of the gear shift device in operation.
It is, therefore, an object of the present invention to provide a gear shift device which includes both an interlock device and a shift lock device which are simple in construction and effective to increase the operation safety of the shift device.